Function analysis of DSI1 responding to abiotic stresses in rice
Xiaoyue Liu, Wensheng Wang, Liyu Huang, Ying Zong, Binying Fu *

Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, 100081.
*Corresponding Author：Binying Fu, fuby@caas.net.cn, Tel: +86 10 82106698, Fax: +86 10 82108559.

Abstract
Drought poses a serious threat to the sustainability of rice (Oryza sativa) yields in rain-fed agriculture. The bHLH transcription factors play important roles in the regulation of plant development and stress response. Here, we report the results of a functional genomics approach that identified a rice bHLH transcription factor gene, DSI1, which improved performance of transgenic rice plants under drought conditions. Overexpression of DSI1 in rice increased the plant tolerance to drought, high salinity, and low temperature at the vegetative stage. Subcellular localization of the GFP- DSI1 fusion protein indicate DSI1 is localized in the nucleus and regulate the expression of related genes. Overall, our results demonstrated that overexpression of DSI1 enhances drought tolerance of transgenic plants, which increases grain yield significantly under field drought conditions.

Key words: bHLH; transcription factor; stress tolerance; functional analysis